The invention relates to an artificial wrist joint enabling flexion and extension movements and distal spherical bearing member with a proximal guide surface attached to the radius and an intermediate member which, at the distal end towards the bearing member, comprises a spherical counter surface and at the proximal end comprises a sliding surface.
An artificial wrist joint is shown in U.S. Pat. No. 4,040,130 in the form of a restricted ball-and-socket joint. There a ball-and-socket joint is connected to several metacarpal bones via a yoke and bone nails. The movement of the ball-and-socket joint is restricted in comparison with an intermediate shell, and the movement of the intermediate shell is restricted in comparison with the bearing shell attached in the radius by grooves disposed so that they intersect one another, in which guide bones slide but cannot twist. The joint permits swivelling about two rigid axes which intersect in the ball-and-socket joint. For a wrist joint the use of such an implant represents great intervention, which is not justified in all disorders of the wrist joint. Especially in arthritic disorders of the wrist joint, when a reduction of the pain takes a priority over a restricted function of the wrist joint, reduced intervention can be an advantage.